This invention relates generally to electrical bus bars and more particularly to a fabricated fuse/bus bar assembly having separate fixed terminals on the bus bar for connection to a pluggable fuse.
Electrical bus bars having integral fuse connectors are in common use in appliances, automobiles etc. and are an essential electrical safety component in many products. These terminal and bus bar components are usually stamped from a single piece of highly conductive material such as a copper alloy metal. The terminals are then formed by bending portions of the stamped metal into the appropriate shape. This type of construction is disadvantaged in that the current capacity and heat dissipation characteristics of the bus bar is limited by the thickness and composition of the material used to fabricate the terminal.
The design requirements for a connector terminal and a bus bar differ substantially. A connector terminal is required to be rigid yet flexible and has a complex configuration best formed from thin sheet metal stock. In contrast, a bus bar needs to be stiff and must carry relatively high current loads. In addition, the thermal conductivity in a bus bar should be high for adequate heat dissipation. Because the current load through each connector is less than the current load through the bus bar, the heat dissipation characteristics of the connector material are not as important as in the selection of the bus bar material.
Accordingly, it is an object of the present invention to provide a fuse/bus bar assembly that can utilize a bus bar of various thicknesses and compositions as the current requirements demand, while utilizing other materials optimized for the fabrication of terminals.
It is another object of the present invention to provide a fuse/bus bar assembly capable of improved current carrying capacity by acting as an effective heat sink for resistive heat load dissipation.
A fuse/bus bar assembly according to the present invention for use typically in an automotive vehicle comprises a one-piece bus bar member of highly conductive material such as a copper alloy having a bus portion and a terminal attaching portion bent at an angle from the bus portion. Attached to the terminal attaching portion, by staking, riveting, or other attachment means, is a metal strip having a terminal formed at each end thereof. A plurality of the metal strips may be attached to the terminal attaching portion forming a series of pairs of the terminals spaced apart along the terminal attaching portion of the bus bar.
The connection between the strip and the terminal attaching portion of the bus bar provides a highly conductive electrical path between the fixed terminals and the bus bar to minimize resistive heating at the transition.
The fixed terminals formed from the metal strips may be male or female terminals for use with a fuse plug having legs of corresponding mating design. If the fuse plug has male terminals, one leg of the fuse plug is inserted into the fixed female terminal attached to the terminal attaching portion. The other leg of the fuse plug is inserted into a discrete female terminal attached to a wire leading to an external circuit load. The fuse/bus bar assembly may be mounted within a plastic connector housing which then is bolted to the vehicle.
The result is a fuse/bus bar that can accommodate terminals formed from metal strips of differing thicknesses and materials depending upon the current capacity required for the individual circuit. The bus bar can be of different thickness or material composition to provide the required current carrying capacity and provide adequate heat dissipation for the entire circuit system. Thus the fuse/bus bar assembly of the present invention provides increased flexibility in power distribution design.
Further objects, features and advantages of the invention will become apparent from a consideration of the following description and the appended claims when taken in connection with the accompanying drawing.